Mmmm...sort of. I mean yes to one and no to the other.

Musk was always a piece of shit human. A look at his life makes this clear. So the "early onset grumpiness" of midlife argument isn't - I don't think - specifically material (and maybe a little bit condescending.)

The money argument is certainly valid...and while all of your points about how they distort the minds of the rich are true, I'm not sure that's really the root cause (at least of someone like Musk.)

Even Musk needed to maintain an image of sanity and normal social functioning early in his career. He needed venture capital, workers, and positive publicity in order to get his projects rolling.

But once he had "made it" and become an icon of success and vision - he didn't really need it that much anymore. He could get the support and capital even if people knew he was a racist, x-phobic piece of shit.

So, he fired whatever publicist was keeping him in check, and let his asshole-light shine.

Was this because he was filthy rich? It was. But it was because his money freed him from the need to continue pretending be normal and likeable.

But did it create this monstrosity. Oh hells no. He was always a POS, he just doesn't need to hide it anymore.

The story is likely the same for Rowling. But I don't know (or care) much about her transphobic ass. So I really can't say :D

JMHO (Just my humble opinion :D)